Tools4Progress by IAP Hamburg (DE)
IAP is mainly active as a software developer, but also sells the tools it uses for these projects. They built tools like pCase to design, develop and maintain your database schema. Or Skin-Client which cleverly replicates an OpenEdge screen in a web context: you develop a screen once and roll it out on various platforms.
The screenshot above is of the development environment OF-1 which is the tool of choice for refactoring legacy software and develop new software.
More info on the IAP website: https://www.iap.de/